Hurricane FRANCES

ZCZC MIATCDAT1 ALL
TTAA00 KNHC DDHHMM
HURRICANE FRANCES DISCUSSION NUMBER 10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 AM EDT FRI AUG 27 2004
FOR A COUPLE OF HOURS BEFORE 0600Z THERE WAS A WELL-DEFINED EYE
EMBEDDED WITHIN A SYMMETRIC AREA OF DEEP CONVECTION. THIS GAVE THE
APPEARANCE OF A STRONGER HURRICANE SINCE OBJECTIVE NUMBERS WERE
NEAR 5.0 AND A SUBJECTIVE CLASSIFICATION WOULD GIVE A 5.5 ON THE
DVORAK SCALE DURING THAT PERIOD. AT THE CLASSIFICATION TIME...06Z...
THE EYE BECAME LESS DEFINED AND CONVECTION WEAKENED A LITTLE. THIS
RESULTED IN THE SAME 4.5 T-NUMBERS THAT WERE PROVIDED AT 00Z.
THEREAFTER...MORE RECENT SATELLITE IMAGES SHOW A RAGGED EYE SO...
THE INITIAL INTENSITY HAS BEEN INCREASED TO 80 KNOTS. THE OUTFLOW
REMAINS VERY WELL ESTABLISHED AND THE OCEAN IS WARM. IN ADDITION...
GLOBAL MODELS DEVELOP A LARGE UPPER-LEVEL ANTICYCLONE OVER/AROUND
FRANCES WITH THE CIRCULATION OF THE HURRICANE EXTENDING UP TO 200
MB. THIS PATTERN IS COMMON IN INTENSE HURRICANES. THEREFORE...
ADDITIONAL STRENGTHENING IS INDICATED. THE INTENSITY FORECAST
ASSUMES THAT THE UNFAVORABLE UPPER-LEVEL WESTERLIES CURRENTLY
OBSERVED IN THE AREA WHERE THE HURRICANE IS EXPECTED TO BE IN 3
DAYS WILL WEAKEN AS SUGGESTED BY GLOBAL MODELS.
FRANCES APPEARS TO BE MOVING TOWARD THE WEST-NORTHWEST OR 295
DEGREES AT 12 KNOTS. THE SUBTROPICAL RIDGE IS EXPECTED TO WEAKEN
TEMPORARILY AS A MID-LEVEL TROUGH MOVES EASTWARD. THIS WOULD RESULT
IN A DECREASE IN FORWARD SPEED AND PERHAPS A TURN MORE TO THE
NORTHWEST. IN FACT...THE HURRICANE MAY BE DOING SO AS WE SPEAK.
HOWEVER...UNANIMOULSY ALL GLOBAL MODELS ARE REBUILDING THE
SUBTROPICAL RIDGE. THIS PATTERN WOULD FORCE THE HURRICANE TO MAKE A
LEFT TURN IN A COUPLE OF DAYS. THE STRENGTH OF THE SUBTROPICAL
RIDGE WILL CONTROL HOW MUCH THE HURRICANE WILL TURN WESTWARD. THE
GFS AND THE CANADIAN GLOBAL MODELS ARE THE MOST AGGRESSIVE BRINGING
THE HURRICANE WESTWARD BASICALLY ALONG 20 NORTH FOR THE NEXT
SEVERAL DAYS. THE UK AND THE GFDL HAVE ALSO SHIFTED THE TRACK MORE
TO THE WEST BUT NOT AS MUCH AS THE GFS. THE OFFICIAL FORECAST IS
HALFWAY BETWEEN THE GFS AND THE UK MODELS. THE TREND OF THE GLOBAL
MODELS SUGGEST THAT THIS HURRICANE MUST BE MONITORED VERY CAREFULLY
OVER THE NEXT SEVERAL DAYS.
ONCE AGAIN...IT SHOULD BE STRESSED THAT 4- AND 5-DAY FORECAST POINTS
CAN EASILY BE IN ERROR BY SEVERAL HUNDRED MILES.
FORECASTER AVILA
FORECAST POSITIONS AND MAX WINDS
INITIAL 27/0900Z 14.5N 48.4W 80 KT
12HR VT 27/1800Z 15.3N 50.3W 85 KT
24HR VT 28/0600Z 16.5N 52.0W 95 KT
36HR VT 28/1800Z 18.0N 53.5W 100 KT
48HR VT 29/0600Z 19.0N 55.5W 100 KT
72HR VT 30/0600Z 20.5N 58.5W 105 KT
96HR VT 31/0600Z 21.0N 61.5W 105 KT
120HR VT 01/0600Z 21.5N 65.0W 105 KT
$$
NNNN